I know the solution has to do something formal power series. I found following pieces: link 1 and link 2 , but even those couldn't get me any further. Also WolframAlpha didn't gave me any clue, though there's some information. I'm completely stuck, which means any help is welcome. Thank you!

Feb 16th 2011, 11:20 AM

TheEmptySet

Quote:

Originally Posted by Greg98

Hello,
the problem is to show by calculating that:.

I know the solution has to do something formal power series. I found following pieces: link 1 and link 2 , but even those couldn't get me any further. Also WolframAlpha didn't gave me any clue, though there's some information. I'm completely stuck, which means any help is welcome. Thank you!

Very formally we have

Now consider

What is

Why does this help?

Feb 16th 2011, 02:29 PM

chisigma

Quote:

Originally Posted by Greg98

Hello,
the problem is to show by calculating that:.

I know the solution has to do something formal power series. I found following pieces: link 1 and link 2 , but even those couldn't get me any further. Also WolframAlpha didn't gave me any clue, though there's some information. I'm completely stuck, which means any help is welcome. Thank you!